Excusable neglect under Rule 4:50-1 has been defined as carelessness attributable to an honest mistake that is compatible with due diligence or reasonable prudence

On motion, with briefs, and upon such terms as are just, the court may relieve a party . . . from a final judgment or order for the following reasons: (a) mistake, inadvertence, surprise, or excusable neglect; . . . (c) fraud (whether heretofore denominated intrinsic or extrinsic), misrepresentation, or other misconduct of an adverse party; . . . or (f) any other reason justifying relief from the operation of the judgment or order.

Although the rule should be used sparingly to revisit judgments of the court, Hous. Auth., supra, 135 N.J. at 283-84; Hodgson v. Applegate, 31 N.J. 29, 37 (1959), motions to vacate default judgments, as opposed to judgments entered after contested litigation, are “viewed with great liberality, and every reasonable ground for indulgence is tolerated to the end that a just result is reached[,]” Marder v. Realty Const. Co., 84 N.J. Super. 313, 319 (App. Div.), aff’d, 43 N.J. 508 (1964).

“Excusable neglect” under Rule 4:50-1(a) has been defined as carelessness “attributable to an honest mistake that is compatible with due diligence or reasonable prudence.” Mancini v. EDS, 132 N.J. 330, 335 (1993).

The Supreme Court has laid out the broad contours of Rule 4:50-1(f):

[N]o categorization can be made of the situations which would warrant redress under subsection (f). . . . [T]he very essence of (f) is its capacity for relief in exceptional situations. And in such exceptional cases its boundaries are as expansive as the need to achieve equity and justice.

Rule 4:50-1 is intended to reconcile the judicial efficiency resulting from treating judgments as final with the equitable principle of permitting courts to avoid injustice in a particular case. . . . [S]ubsection (f) is to be used “sparingly” and only “in situations in which, were it not applied, a grave injustice would occur.”